Assuming your playing for fun do what you enjoy most.
There isn't enough quality sit n go's consistantly filling on 888 for it to sustain a player an income.
By quality I mean high enough buy in non turbo SnG's
The only bonus is their are so many weak players. To be honest I think any true full time grinder realises this and moves on to pokerstars
or one of the bigger sites for sit n go's and tournaments.
Im not doubting you can make some big bucks on 888 over time, but it's more important to be selective with your sit n go's tournaments,
and cash if you can play cash.
Satellites are an excellent way to go you wanna be playing in those big weekly tournaments making some serious moves for your shot at a big score or a live ticket,